Semiconductor devices are used in a variety of electronic applications, such as personal computers, cell phones, digital cameras, and other electronic equipment, as examples. Semiconductor devices are typically fabricated by sequentially depositing insulating or dielectric layers, conductive layers, and semiconductive layers of material over a semiconductor substrate, and patterning the various material layers using lithography to form circuit components and elements thereon. Dozens or hundreds of integrated circuits are typically manufactured on a single semiconductor wafer. The individual dies are singulated by sawing the integrated circuits along a scribe line. The individual dies are then packaged separately, in multi-chip modules, or in other types of packaging, for example.
The semiconductor industry has developed many ways in which dies can be packaged. In recent years, dies and/or packages containing a die are frequently attached to some other substrate, package, die, or interposer using solder balls or bumps. In many of these applications, an underfill material is used to fill the space between the die/package and other component. By filling the space, the underfill is thought to provide greater mechanical integrity to the bond by providing additional bonding and support to the balls or bumps.